Cold space door



April 1966 1. s. HOUVENER ETAL 3,243,855

COLD SPACE DOOR Filed Feb. 8, 1965 m 0 S v/ r J w 5 w m I m w O 2 M 2 IWNW 5 4 )12 United States Patent Office 3. .85 COLD SPACE DOOR 4 IrvingS. Houvener, Houghtoir Lake, and Albert J. Palfey, Midland, Mich,assi'gnor's to The Dow Chemical Com pany, Midland, Mich, a corporationof Delaware Filed Feb, 8, 1965, SenNo. 436,402 4 Claims. (CI. -35) Thisapplication is a continuationdn-part of copending application Serial No.250,836 filed January 11, 1963, now abandoned.

This invention relates to an improvement in cold space doors, of theinsulated type, such as used on refrigerators, walk-in cold storagerooms, and the like.

A cold space door, of the type with which this invention is concerned,is subjected tostra-ins caused by a temperature differential resultingfrom temperature differences between theinner and outer panels of thedoor. Such a temperature differential can cause warpage resulting inleaks and/ or damage or the doorsuch as by crackiiig, especially wherethe temperature differential is quite severe, thus rendering the doorinefficient, or inoperative.

It is therefore an object of this invention to provide a cold space doorwhich will not be warped or damaged by temperature differential betweenthe and outer shell of the door.

Another object of this invention is to provide a cold space door whichcounteracts temperature differential to which the door is exposed, byallowing unrestrained relative expansion and contraction between thedoor inner and outer shells.

Still another object is to provide a cold space door wherein assemblagemay be effected without use of fastening means, or welding. v V

Other objects of the invention will in part be obvious and will in partappear hereinafter.

Briefly, the cold space door of the present invention solves the problemof counter-acting temperature dif-' ferential, by allowing unrestrainedexpansion, or contraction, of the door inner and outer shells relativeto each other. This is accomplished by arranging the peripheral edge ofthe door outer shell so that it overlaps the peripheral edge of the doorinner shell in a manner which allows relative sliding movementtherebetween. A rigid insulating material is disposed in andsubstantially fills the space between the inner and outer door shells toposition the inner shell and outer shell in spaced relationship, withthe inner shell in sliding contact with the peripheral edge of the outershell. A sheet of flexible insulation is positioned in a compressedstate bet-ween the rigid insulating material, and the periphery of theinner shell to forcibly urge the inner shell in sliding engagement withthe outer shell. Among the other features of the door is the manner ofassembly wherein no fastening means, or welding, is required.

The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts which will beexemplified in the construction hereinafter set forth, and the scope ofthe invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the acoompanying drawings, in which:

FIGURE 1 is an elevation view of a cold space door embodying theprinciples of the invention; and

FIGURE 2 is an enlarged section view generally as seen along line 22 inFIG. 1.

Similar reference characters refer to similar parts throughout theseveral views of the drawing.

Referring now to the drawing, numeral 6 identifies a door illustrativeof an embodiment of the invention which door is mounted by hinges 8, toenclose an opening 10 of a cold storage room defined in part by aninsulated wall -12. A bar-type lock, including a bar or latch '14,

ing-10, all as is well known to those skilled in the art.

The door 6 includes an outer shell 20 secured to a door frame 22 theperipheral edge of which bent, or spun over on assembly, to provide aninwardly extending flat surface24, and a dished inner shell 26 formed toprovide, a flange portion having a flat peripheral surface 28 a por tionof which is in sliding engagementwith the outer shell sunface 24. Anoverlapping relationship is thus provided at the peripheral regions ofthe shells which affords sliding contact therebetween. The material ofthe inner shell maybe plastic or metal sheet. In certain installations,the frame 22 may be omitted and the outer shell may be bent over toprovide the overlapping peripheral edge as required for slidingengagement with the inner shell.

Insulating material 30 preferably made of a plastic foam which is quiterigid, such as polystyrene, or polyethylene, is positioned between theouter shell 20 and inner shell 26 and substantially fills the spacether'ebetween to maintain the shells 20 and 26 in spaced relationshipand the peripheral edge of surface 24 of the inner shell 26 in slidingcontact with thev periperal edge or surface 28 of the outer shell 20. Asheet of flexible insulation 32, which is easily compressible and haselastic recovery, which may be made of rubber, or equivalent, isarranged in a compressed state between the insulating material 30, andthe outer portion or the inner shell 26. The insulating material 30forcibly urges the flat peripheral edge or surface 24 of the inner shell'26 in sliding engagement with the flat peripheral edge or surface 24 ofthe outer shell 20.

An adhesive substance is applied to the surfaces of the insulatingmaterial 30, or to the surfaces with which the insulating material willcontact upon assembly, whereby the door will be maintained in assembledcondition, with the surfaces 24 and 28 in sliding engagement. A doorsealing means 34 is provided between the periphery of the door 6 and theopening 10, which sealing means may be affixed to either the door, orthe door opening, and which may be a rubber gasket, or a magnetic typeof seal, as sometimes used in cold space door installations.

From the foregoing it will be seen that the door 6 will allowunrestrained expansion or contraction of the inner shell 26, and outershell 20 due to temperature differential, without danger of warpage ordamage of the door, since the shells are positioned for relative slidingmovement by virtue of the engagement of surfaces 24 and 28. Thecompressible insulation .32 allows for relative movement of the shellsdue to temperature differential. It will also be noted that the door 6may be assembled without the use of fastening means, or welding.Attention is directed to the fact that the peripheral edge of the innershell 26 is spaced from the enclosing portion of the outer shell 20, sothat it is free to expand without contacting or abutting the outershell. This is an important feature of construction, since it avoids anystrain placed upon the shells due to dimensional change as a result oftemperature differential.

From the foregoing it will be seen that the door 6 will satisfy all ofthe objectives set forth hereinbefore.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efliciently attained and,since certain changes may be made in the above construction withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the ac- PatentedApr. 5', 1966- companying drawing shall be interpreted as illustrativeand not in a limiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention, which, as amatter of language, might be said to fall therebetween.

Now that the invention has been described, what is claimed as new. anddesired to be secured by Letters Patent is:

1. A door construction comprising in combination, an inner shell and anouter shell, said .outer shell having formed about its periphery anoverlapping engagement with said inner shell to provide a slidablecontact surface between said shells, a rigid insulating materialpositioned between said inner and outer shells and a sheet of flexibleinsulation which is easily compressible and has elastic recoveryarranged in a compressed state between said rigid insulating materialand the outer edge portion of said inner shell whereby the door will bemaintained in assembled condition and said inner shell shall be insliding engagement with said outer shell at said slidable contactsurface.

2. A'door construction comprising in combination, a dished inner shellhaving a flanged portion with a flat peripheral surface, an outershellhaving a bent peripheral surface which overlaps said flatperipheral surface of said flange to retain said inner shell Within saidouter shell and to provide a slidable contact surface for said innershell for allowing said inner shell to freely move relative to saidouter shell, a rigid insulating material positioned between said innerand outer shells and a sheet of flexible insulation which is easilycompressible and has elastic recovery arranged in a compressed statebetween said rigid insulating material and the periphery of said innershell whereby the door .will be maintained in assembled condition andsaid inner shell shall be in sliding engagement with said outer shell atsaid slidable contact surface.

3. A door construction comprising in combination, an

inner shell and an outer shell, said outer shell having formed about itsperiphery an overlapping engagement with said inner shell to provide aslidable contact surface between said shells, a rigid insulatingmaterial positioned between said inner and outer shells and a sheet offlexible insulation which is easily compressible and has elasticrecovery arranged in a compressed state between said rigid insulatingmaterial and the outer edge portion of said inner shell whereby the doorWill be maintained in assembled condition and said inner shell shall bein sliding engagement with said outer shell at said slidable contactsurface to counteract temperature differential, by allowing unrestrainedexpansion, or contraction, of the inner and outer shells relative toeach other.

4. A door construction'comprising in combination, a dished inner shellhaving a flanged portion with a fiat peripheral surface, an outer shellhaving a bent peripheral surface which overlaps said flat peripheralsurface of said flange to retain said inner shell within said outershell and to provide a slidable contact surface for said inner shell forallowing said inner shell to freely move relative to said outer shell, arigid insulating material positioned between said inner and outer shellsand a sheet of flexible insulation which is easily compressible and haselastic recovery arranged in a compressed state between said rigidinsulating material and the periphery of said inner shell whereby thedoor will be maintained in assembled condition and said inner shellshall be in sliding engagement with said outer shell at said slidablecontact surface to counteract temperature differential, by allowingunrestrained expansion, or contraction, of the inner and outer shellsrelative to each other.

References Cited by the Examiner V UNITED STATES PATENTS 2,622,75412/1952 Eagels'. 2,878,534 3/1959 Josaitis 20-35 3,078,003 2/1963Kesling 20-35 REINA'LDO P. MACHADO, Primary Examiner.

HARRISON R. MOSE'LEY, Examiner.

1. A DOOR CONSTRUCTION COMPRISING IN COMBINATION, AN INNER SHELL AND ANOUTER SHELL, SAID OUTER SHELL HAVING FORMED ABOUT ITS PERIPHERY ANOVERLAPPING ENGAGEMENT WITH SAID INNER SHELL TO PROVIDE A SLIDABLECONTACT SURFACE BETWEEN SAID SHELL, A RIGID INSULATING MATERIALPOSITIONED BETWEEN SAID INNER AND OUTER SHELLS AND A SHEET OF FLEXIBLEINSULATION WHICH IS EASILY COMPRESSIBLE AND HAS ELASTIC RECOVERYARRANGED IN A COMPRESSED STATE BETWEEN SAID RIGID INSULATING MATERIALAND THE OUTER EDGE PORTION OF SAID INNER SHELL WHEREBY THE DOOR WITH BEMAINTAINED IN ASSEMBLED CONDITION AND SAID INNER SHELL SHALL BE INSLIDING ENGAGEMENT WITH SAID OUTER SHELL AT SAID SLIDABLE CONTACTSURFACE.